(nzvi) (// // ). ph.. XRD (SEM) ph. ( -).. ph. : Synthesis of Zero Valent Iron Nanoparticles (nzvi) and its Efficiency in Arsenic Removal from Aqueous Solutions Ali Reza Rahmani 1 Hamid Reza Ghafari 2 Mohammad Taghi Samadi 3 Mansour Zarabi 4 (Received Feb. 5, 21 Accepted Sep. 14, 21) Abstract The aim of this study to synthesize nanoparticle zero valent iron and to determine its efficiency in arsenic removal from aqueous solutions. Nanoparticles were synthesized by reduction of ferric chloride using sodium borohydrid. The experiments were conducted in a batch system and the effects of ph, contact time, and the concentrations of arsenit, arsenat, and nano zero valent iron were investigated. SEM and XRD were applied for the determination of particle size and characterization of the nanoparticles synthesized. SEM results revealed that synthesized particles were of nano size (1-1 nanometers). At ph=7., 99% of arsenit and arsenat was removed when nano zero valent iron concentration was 1 (g L -1 ) over a retention time of 1 min. Based on the results obtained, the removal efficiency was enhanced with increasing nano zero valent iron dosage and reaction time, but decreased with increasing initial concentration and initial solution ph. The significant removal efficiency, high rate of process and short reaction time showed that iron nano particles are of a significant potential for the removal of arsenic from aqueous solutions. Keywords: Nanoparticle, Iron, Arsenic, Aqueous Solution. 1. Assoc. Prof., Dept. of Environmental Health Eng., Research Center for Health Sciences, School of Public Health, Hamadan University of Medical Sciences, Hamedan 2. Faculty Member of Environmental Health Eng., School of Public Health, Hormozgan University of Medical Sciences (Corresponding Author) (+98 811) 826661 ghaffarihrz@gmail.com 3. Assist. Prof., Dept. of Environmental Health, School of Public Health, Hamadan University of Medical Sciences, Hamedan 4. Grad. Student of Environmental Health Eng., Faculty of Public Health Hamadan University of Medical Sciences, Hamedan - - ghaffarihrz@gmail.com () ( ) - - 35
PRBs..[] ZVI. X ZVI.[] ZVI As() As(III) As(V) As(III). Fe As(V) As(III). As(V) As(III).[] Fe. ZVI (nzvi) nzvi.[].[-] TCE -. nzvi. nzvi. PRBs. 6 Nanoparticle Zero Valent Iron -.[-]...[ ]..[ ] µgl 1 2 ( H3AsO3, H 2AsO3, HAsO3 ) 2.[-] ( H3AsO4, H2AsO4, HAsO4 ) -.[ ].[] ) ( Al Sn Zn Fe. (ZVI) As(V) As(III).[- ]. ZVI (PRBs) PRBs. 1 World Health Organization (WHO) 2 US. Environmental Protection Agency (USEPA) 3 Zero Valent Iron (ZVI) 4 Permeable Reactive Barrier 5 In Situ 36
--.. ± ) ( ) ph. / / /) ( ) (. (.. / SDDC(35-As) UV-17 UV- VISIBLE.[] - --. SEM XRD. 1 Shimadzo ph nzvi.. - -- ( NaBH 4 ) / ( FeCl3.6H 2O ) - /. / ( NaOH ).... Fe Fe +2 2FeCl3 + 6NaBH4 + 18H 2O 2Fe(s) () + 6B(OH) 3 + 21H 2 + 6NaCl... (XRD) X SEM. SEM - 37
C C %E = 1 () C C C. ph.. /. 2θ= / / / / - ICDD Card # 2θ=/. (FeOOH). Fe ICDD Card # = - --. 12 1 Intensity(Counte) 8 6 4 (%) 1 8 6 4 2 2 5 1 15 2 25 3 35 4 45 5 2 Teta (deg) nzvi=.1 g/l nzvi=.5 g/l XRD - nzvi=.25 g/l nzvi= 1 g/l 2 5 1 15 ( ) (%) 1 8 6 4 2 nzvi=.1 g/l nzvi=.5 g/l nzvi=.25 g/l nzvi=1 g/l 2 5 1 15 ( ) ph=7 : - 1 mgl -1 = (%) 1 8 6 4 2.1.25.5 1 ( ) ( % ) 1 8 6 4 2.1.25.5 1 ( ) : ph - mgl -1 38
(%) 1 8 6 4 2 2 5 1 15 ( ) (%) 1 8 6 4 2 2 5 1 15 () :C nzvi=1gl -1 ph - = mgl -1 (%) 1 8 6 4 2 1 5 1 15 2 25 3 ( ) (%) 1 8 6 4 2 1 5 1 15 2 25 3 ( ) : - ph= C nzvi=1 g L -1 - ph.... ph.[].[ ].. ( ) ph.. ph / ph. ( ) ph. ph /.... 39
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